4  Marine Heatwaves 2024

Code
import sys

sys.path.append('../../')
from script_IDS import fun_script_IDS

import pandas as pd

cciea_yr = 2024


fn_meta = './metadata.csv'
df1 = pd.read_csv(fn_meta)
cell2_wnt = ['Component_Section', 'Subcomponent', 'ERDDAP_Dataset_ID', 'PI', 'Contact']

ds_id_hc = 'cciea_OC_MHW'
ts_id_list = ['cciea_OC_MHW_HC']
vec2_hc, ds_id_lbl_hc, rgn_lbl_hc = fun_script_IDS(df1, cell2_wnt, ds_id_hc, ts_id_list)

ds_id_ma = 'cciea_OC_MHW'
ts_id_list = ['cciea_OC_MHW_MA']
vec2_ma, ds_id_lbl_ma, rgn_lbl_ma = fun_script_IDS(df1, cell2_wnt, ds_id_ma, ts_id_list)

ds_id_mi = 'cciea_OC_MHW'
ts_id_list = ['cciea_OC_MHW_MI']
vec2_mi, ds_id_lbl_mi, rgn_lbl_mi = fun_script_IDS(df1, cell2_wnt, ds_id_mi, ts_id_list)

Description     Marine heatwaves (MHW) occur when ocean temperatures are much warmer than usual for an extended period of time; they are specifically defined by the difference between the current temperature and the expected temperature for a specific location and time of year [1]. MHWs are a growing field of study worldwide because of their effects on ecosystem structure, biodiversity, and regional economies.

Indicator Category     Climate and Ocean Drivers

Data Steward     Schroeder

Erddap Dataset ID     cciea_OC_MHW, cciea_OC_MHW, cciea_OC_MHW

CCIEA timeseries ID     cciea_OC_MHW_HC, cciea_OC_MHW_MA, cciea_OC_MHW_MI

Region     NA, NA, NA

Public availability statement     Source data are publicly available.

Additional Information     There is growing recognition that marine heatwaves can have strongly disruptive impacts on the CCE (Morgan et al. 2019). Based on an analysis of sea surface temperature anomalies (SSTa) obtained from satellite measurements (OISST); we define marine heatwaves as 1.0 times when normalized SSTa >1.29 s.d. (90th percentile) of the long-term SSTa time series at a location, and lasts for >5 days; which are analogous to the thresholds suggested in Hobday et al. (2016). Here, we further report on statistics concerning large heatwaves (LHW) which were tracked through space and time, with LHW defined as those heatwaves with an area > 400,000 km2 (these denote the top 20% of all heatwaves by area as measured since 1982 when satellite data became available for tracking. For more information on MHW see https://www.integratedecosystemassessment.noaa.gov/regions/california-current/california-current-marine-heatwave-tracker-blobtracker.

Figures

Figure 4.1: Monthly average of MHW time series.




(a) Heatwave Cover

 

(b) Sum Area

 

(c) Intensity
Figure 4.2: Seasonal averages of the monthly MHW time series.

2024 Conditions

References

Hobday, Alistair J, Lisa V Alexander, Sarah E Perkins, Dan A Smale, Sandra C Straub, Eric CJ Oliver, Jessica A Benthuysen, et al. 2016. “A Hierarchical Approach to Defining Marine Heatwaves.” Progress in Oceanography 141: 227–38.
Morgan, Cheryl A, Brian R Beckman, Laurie A Weitkamp, and Kurt L Fresh. 2019. “Recent Ecosystem Disturbance in the Northern California Current.” Fisheries 44 (10): 465–74.